Fender M-80

[pchilson]

Hi,

I recently picked up a Fender M-80 SS amp. It is in excellent physical and working condition with the exception of the power on LED which is out. Enzo was kind enough to email me a schematic for the amp and the parts list shows this LED as being "LED Red, 5x5mm". I have a spare on hand Red LED that is 3mm (don't know any more than that). Would this 3mm LED work?

Another thing. The amp sounds good on the Normal channel, if not a bit dark. I ran it through an external cab and it is the speaker. The Drive channel is also good sounding until you get the gain knob going past 4 then it just starts sounding ratty. Is there component values that can be altered to give the gain a somewhat smoother sound to it?

Hoping to hear your thoughts and suggestions.

Thanks

[Enzo]

The 5x5mm LED sits in the hole in the panel and fills it up. Electrically they are the same, and don';t matter, but a round 3mm LED won't look as neat in the panel hole.

[Gtr_tech]

I can't give any specifics since I rarely do any mods to SS gear, but generally what you need to do is decrease emphasis on low end in the cascaded gain sections. Too much low end translates into the ratty/choppy sound you describe. Note that is will not really decrease the amount of low end, harmonics generated by the cascaded stages will still create plenty of low end. You just want to de-emphasise it until the last stage. You might try decreasing the drive signal between stages as well. Its hard to say what the magic solution is without having the chassis on front of me to play with.